Update How-To: Handle large http body requests to new max-body-size command

[fabistb]

Describe the issue
The documentation points to the outdated / deprecated http-max-request-size annotation / flag.
It should point to the newer max-body-size.

URL of the docs
https://docs.dapr.io/operations/configuration/increase-request-size/

Expected content
The http-max-request-size to max-body-size and add the information that this will also affect gRPC

Screenshots